EDITAR: Parece que as variações abaixo são de um conto de fadas chamado A Filha do Troll, , incluída por Andrew Lang no Pink Fairy Book . Do resumo da Wikipedia:
Deep in the sea, he found a palace where a beautiful maiden lived.
...
Then he should offer to pay the king's debts in return for coming;
once he came, he would make trouble for the troll until it demanded
the king answer three questions for his life. They would be where his
daughter was, and then to pick her out, and then to find the troll's
heart, which was in a fish.
He went back to the troll and refused to stay in his service. He
served the king and did as the troll's daughter had said. When he got
to the troll's castle with the king, he broke all sorts of glass
things. Then he answered the troll's questions. When he picked out his
daughter, the maiden appeared and stayed by him; when he picked out
the fish the maiden indicated, he cut it open and killed the troll.
Resposta original:
Com crédito completo para a resposta da Valorum, parece que uma tradução em inglês pode ser encontrada aqui ( Danish Fairy Tales por Svend Grundtvig, tradução por J. Grant Cramer). Ebook no domínio público aqui .
A história é chamada A Filha do Mago .
...the wizard will sentence him to death in spite of the fact that he
has paid his debt, unless he can answer correctly questions that my
father will put to him. The first question that my father will ask,
will be: 'Where is my daughter?' Then you must step forth and say,
'She is at the bottom of the sea.' He will also ask whether you can
recognize her, and you must answer, 'Yes.' Then a large number of
young women will be led past you in order that you may point out which
one you take to be his daughter. As you might not recognize me, I
shall nudge you as I pass, and you must immediately seize me and hold
me fast. The wizard's next question will be, ' Where is my heart?' and
you must again step forward and answer, 'It is in a fish.' He will
then ask, 'Do you know this fish?' and you must again answer, 'Yes.'
Then he will have all kinds of fish appear before you, and you will
have to choose the right one from among them. But I will take good
care to be by your side and when the right fish comes I will touch you
gently, and you must seize him and quickly cut him open. Then the
wizard will be discouraged and will ask you no more questions.
Também pode ser esta versão da mesma história de Chris Conover intitulada A Filha do Mago: Uma Lenda Viking. De Goodreads resenhas:
In it an evil Wizard has taken away all the animals from the land and
is pushing human-kind to starvation. There is a strong-hearted young
man and a hidden princess and a test. The test is what lodged the
story so firmly in my mind. The Wizard hid his heart in a fish and to
save his own life the young man must find this fish. Of course he does
and everyone lives happily ever after.